Heat exchanger for fuel fired furnaces



FIG. 1 is a front perspective view of the heat exchanger for fuel fired furnaces;

FIG. 2 is a right side elevational view thereof, which is a mirror image of its left side elevational view;

FIG. 3 is a rear end elevational view thereof;

FIG. 4 is a front end elevational view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a heat exchanger for fuel fired furnaces, as shown and described. 